05 July 2018

The Big Life In Between Grains

Photo from Entouriste

Let's imagine ourselves walking along the shore, adoring this stretch of white sand.

What do you see? Apparently, it's too tricky to tell. 

Only if we find ourselves curious and play with the sand for a bit we'll be able to spot some critters. There could be hermit crabs trotting along, worms making tunnels, and seaweeds washing ashore. Or there could be a seabird waiting for its meal. 

But for the most part, life on the shore seems quiet and empty.

Now, if we change the scenery and make a visit to a busy thriving forest, how would our "lifeless" beach compare?

As anyone who's been in a forest, it's easy to tell the animals are there. We can tell there are cicadas, birds, earthworms, a variety of plants, and fascinating insects we don't know about. We know it's alive from the cacophony of sounds and colors.

In fact, Professor E.O. Wilson remarks that, when we put a cap on all the living terrestrial groups, only seven different phyla exist in the woods [1].

But when we drench our feet in sand and foam, it's a different story...

“The surf may at first seem lifeless, composed of water and soil and washed clean. The opposite is true … among the grains of sand in the surf zone, you will in time find twice the number of phyla." -E.O. Wilson

The beach, in fact, holds 14 different phyla against the seven in the forests. Professor Wilson talks about diversity here, not population in numbers [1].

Who knew that the sand alone hosts an impressive universe of little, wriggling creatures down our feet? 

The Interstitial Breathes

These invisible organisms breathing in between grains are called meiofauna (smaller than 1 mm but larger than about 45 microns), and they comprise as Wilson calls the "little-known planet." 

Purely meiofaunal organisms alone make up five out of the 34 recognized phyla in the animal kingdom. They are literally a thriving empire of organisms
one footprint of moist sand carries as big as 50,000 to 100,000 individuals [2].

These meiofaunagastrotrichs, kinorhynchs, gnathostomulids, loriciferans,  nematodes, priapulids,  rotifers, tardigradesare easy to overlook but they're actually there, clinging for life, clad with smart adaptations suitable for a life in the interstitial.

They're small but they boast complex physiology comparable to the relatively huge macrofauna. They have also developed an array of adaptations to their ever-shifting habitats: Tardigrades (water bears) have claws and suction in their toes to grip on grains; kinorhynchs use their spine-bearing mouth to hook into sand or mud; free-living nematodes possess slender bodies, easing in between grains and use thread-like setae to hold on to their substrate; gastrotrichs are known to hang too tight to their substrate with a strong adhesive.

Check out this creative and interactive infographic (Hakai Magazine) of some meiofauna and the challenges they face in their big world [3].

Photo of a gastrotrich (David Scharf/Corbis, Hakai Magazine)

The Beach We Came to Know

Meiofauna bridge important links in benthic food webs. Aside from serving as important food to many organisms, they are key decomposers which feed and break down detritus, thus keeping microbial communities active and enhancing nutrient recycling. Through bioturbation and burrow construction (plus their sheer number) they render stability to our benthic ecosystems and shape them as we have them today [5].

Ultimately, these make them the very life of the beach: without meiofauna, our beach is but a mire of untouched, organic debris [2].

A clear grasp of their number and diversity, though, remains to be seen. Wilson says we haven't even come close to documenting all of them; there's just a lot to learn and new worlds to discover [1]. And new ways of seeing things, too. 

The next time we go the beach and grab a fistful of sand, we know we're not alone
a multitude of organisms keep us company, living their big lives in between grains. 

If you have more information on meiofauna and other non-fish organisms, we'll be happy to have you as one of SeaLifeBase collaborators. Let us know by sending us an email or visiting our FaceBook page.

[1] Krulwich, R. (2016, March 3). An empty beach isn't empty at all. National Geographic. Retrieved from http://bit.ly/1Umi4SB

[2] Mason, A. (2016, March 21). The micro monsters beneath your beach blanket. Hakai Magazine. Retrieved from http://bit.ly/2vi5aPL

[3] Mason, A., Garrison, M. & Kingdon, A. (2017, April 28). Life interstitial. Hakai Magazinehttp://bit.ly/2w5DLxW

[4] Gerlach, S. A. (1978). Food-chain relationships in subtidal silty sand marine sediments and the role of meiofauna in stimulating bacterial productivity. Oecologia33(1), 55-69.

[5] Schratzberger, M. & Ingels, J. Meiofauna matters: the roles of meiofauna in benthic ecosystems. Retrieved from https://bit.ly/2KP4hCz

05 June 2018

Symbiosis special: What makes the Hawaiian bobtail squid glow?

Photo by Todd Bretl, Monterey Bay Aquarium
As adorable as the endemic Hawaiian bobtail squid Euprymna scolopes can be, its famed relationship with a microbe is even more special: among thousands of marine bacteria, only one microbe, Vibrio fischeri, is known to successfully colonize the squid's light organ within its mantle, turning the squid into an enchanting and 'disappearing' luminescent creature [1-4,8]. 

Few hours after the hatchlings are out from their egg case, V. fischeri from the surrounding water begin to enter the pores on either side of the light organ, settling on the epithelium-lined inner crypt spaces (tiny spaces within the organ)  [1,2,5].

Specificity is achieved early on through a mutual dialogue between the young host and the symbiont (i.e., agreement on entry and attachment of the microbe). Once the microbes have established, this transformation triggers a series of biological changes in both organisms, strengthening their relationship [7].

Now, the squid matures, and as if charging a weapon for the night, V. fishceri reaches its highest concentration in the light organ. And the squid shines its brightest [2,6].

While the squid hunts for prey, the microbes perfectly match the intensity of the moonlight welling down from above, reducing the squid's silhouette, ultimately giving it an 'invisibility cloak' (counter-illumination) against predators seeing from below [5,8]. What's more interesting is that the host is equipped not only to detect but to also control the amount of light emitted by the bacteria through its specialized light organ features [5]. 

Here's a video from Ed Yong (The Atlantic), illustrating this fascinating partnership.

As the dawn breaks, it secretes from its light organ a thick mucous containing 95% of its symbionts back into the sea, while the rest of the microbes replenish themselves to start another cycle [2,6]. Over the rest of the day, the squid becomes dormant and retreats into the sand [6].

For over 20 years, this squid-vibrio relationship has been key in studying many biological phenomena, like cephalopod development and the structure of tissue interacting with light [6]; this one-on-one connection has also been crucial in understanding host-microbe interactions in a natural microenvironment [1,2]. 

Beyond this, the squid-vibrio partnership is important, because, it turns out, the microbe 'remakes' and protects its host: reaching the adult state is only possible when the squid harbors the right microbial ally [8]. 

And, charmingly, the squid need not look further.

To know more about bobtail squids, visit SeaLifeBase.

[1] Rader, B. A., & Nyholm, S. V. (2012). Host/microbe interactions revealed through “omics” in the symbiosis between the Hawaiian bobtail squid Euprymna scolopes and the bioluminescent bacterium Vibrio fischeriThe Biological Bulletin, 223(1), 103-111.

[2] Schleicher, T. R., & Nyholm, S. V. (2011). Characterizing the host and symbiont proteomes in the association between the Bobtail squid, Euprymna scolopes, and the bacterium, Vibrio fischeriPLoS One, 6(10), e25649.

[3] Boettcher, K. J., & Ruby, E. G. (1990). Depressed light emission by symbiotic Vibrio fischeri of the sepiolid squid Euprymna scolopes. Journal of Bacteriology, 172(7), 3701-3706.

[4] Yazzie, N., Salazar, K. A., & Castillo, M. G. (2015). Identification, molecular characterization, and gene expression analysis of a CD109 molecule in the Hawaiian bobtail squid Euprymna scolopesFish & Shellfish Immunology, 44(1), 342-355.

[5] Peyer, S. M., Pankey, M. S., Oakley, T. H., & McFall-Ngai, M. J. (2014). Eye-specification genes in the bacterial light organ of the bobtail squid Euprymna scolopes, and their expression in response to symbiont cues. Mechanisms of Development, 131, 111-126.

[6] McFall-Ngai, M. (2014). Divining the essence of symbiosis: insights from the squid-vibrio model. PLoS Biology, 12(2), e1001783.

[7] Visick, K. L., & McFall-Ngai, M. J. (2000). An exclusive contract: specificity in the Vibrio fischeri-Euprymna scolopes partnership. Journal of Bacteriology, 182(7), 1779-1787.

[8] Yong, E. (26, Jan 2018). The lovely tale of an adorable squid and its glowing partner. The Atlantic. Retrieved from https://www.theatlantic.com/science/archive/2018/01/the-lovely-tale-of-an-adorable-squid-and-its-glowing-partner/551549/

05 April 2018

FishBase and SeaLifeBase sign MoU with World Register of Marine Species (WoRMS)

Databases are rich sources of information, serving not only as learning tools, but a means toward fruitful collaborations and a catapult in advancing scientific research.

This has been the very aim when World Register of Marine Species (WoRMS), FishBase, and SeaLifeBase have officially formed a collaboration last March 2018 to best serve the scientific community.

Last September 2017, the WoRMS Data Management Team attended the 15th International FishBase Symposium in TervurenBelgium. The meeting focused on WoRMS’ underlying database Aphia and its potential use in global, regional and thematic registers, along with LifeWatch Taxonomic Backbone.

The team discussed the existing collaboration between FishBase and WoRMS, wherein FishBase has served as the taxonomic resource for fish names in WoRMS. Building on the ties that have strengthened both databases, the WoRMS team expressed their intention to also document in their database the fish distributions and traits from FishBase.

During the consortium meeting, the team has also seen the potential of FishBase's sister-database, SeaLifeBase—a joint project of the Sea Around Us (University of British Columbia, Vancouver, Canada) and the FishBase Consortium—in providing biological and ecological information of global non-fish species, which can then be maximized for biodiversity and ecosystem studies. WoRMS, in turn, would provide its taxonomic backbone to SeaLifeBase. 

Related links:
WoRMS-Q-quatics MOU

SeaLifeBase is on the lookout for a Research Assistant

Quantitative Aquatics, Inc. is hiring a Research Assistant I for SeaLifeBase, a database documenting all marine non-fish species of the world. 

Kindly see below the details for your reference. 

13 September 2017

Collaborator of the Month: Dr. Charlie (J.E.N) Veron

If you have worked on corals and coral reefs, then you're probably well acquainted with the most comprehensive resource for corals there is, the 3-volume Corals of The World by John Edward Norwood Veron or as cited in the scientific community, J.E.N or Charlie Veron. Can you imagine your life without such a valuable resource? The thing is, Charlie Veron almost did not become a scientist. 

He is known today as the "Godfather of Coral" and likened by David Attenborough to Charles Darwin.

In his memoir A Life Underwater, Charlie chronicles his love for marine life as a child, his long holdup (how he almost didn't make it back to the sea), how one chance helped him pursue his true passion, and how he became a revolutionary self-taught coral specialist.

His work has been instrumental in our present understanding of coral reefs, from how they reproduce to how they evolve, and how they, in the light of climate change, have been dying. "Without his early work we wouldn't have had the basic benchmarks to see the nature of the changes that we are now seeing. He provided that baseline to put everything in context," says the scientist Tim Flannery [1].

Veron's contributions to coral reefs and marine biology are monumental. He was the first to compile a global taxonomy on corals. Also, contrary to common notion, he shed light that the the Indo-Philippines archipelago has the most diverse corals in the world, not the Great Barrier Reef. He is also known for his seminal theory, Reticulate evolution, on how corals have evolved [1]. 

To date, he he has worked on all the major coral reef regions of the world and has over 100 research publications, including 12 books and monographs on corals and coral reefs. 

Among his many books, his three-volume Corals of the World (2000), with his permission to use data and photos, has been invaluable to documenting the diversity of reef-building corals in SealifeBase. 

Over his 50-year career, Veron hasn't only been an insatiable learner of corals. He's been fearless in protecting the marine life he has reveled in his whole life. 

In his memoir, his adventures urge us not only to guard scholarly independence, but more importantly to learn to be persistent and take risks. He explains why today is the most pivotal time to protect our incredible marine life.

You may purchase Charlie's delightful memoir through this link.
[1] Elliott, T. (2017, July 14). Live near the beach? Coral reef expert Charlie Veron has some advice for you. The Age. Retrieved from http://bit.ly/2vFfOMo